Question

A web server hosting company advertises 99.999 percent guaranteed network uptime. (a) how many independent network servers would be needed if each has 98 percent reliability? (round your answer up to the nearest whole number.) network servers (b) how many independent network servers would be needed if each has 89 percent reliability? (round your answer up to the nearest whole number.) network servers

Answer 1

Instead of thinking about reliability think of failure. 99.999% reliability =0.00001 chance of failure. And 95% reliability =0.05 chance of failure. Assuming failures are independent (they probably are not) the chance of n servers failing is (0.05)n Find n such that (0.05)n=(0.00001) now do it for (0.14)n=(0.00001)